In bone repair, continuous loops of material may be used as tethers to anchor bone sections together. Several loop sections may be needed to hold bone sections in place while they set, especially in situations where the bones have broken in more than one place. Another application involves the securing of spinal vertebrae. In certain spinal surgeries, two adjacent vertebras are pulled together. This is accomplished by inserting screws or other rigid attachment devices into each vertebra and then using a length of fiber, yarn, suture or other configuration of material to loop around both devices to help hold the bones together. It is advantageous to use continuously looped fibers rather than a single length joined together where there are two end points to connect. Moreover, the use of continuous loop fiber provides a level of consistency and reliability in the length of the loop that is advantageous in surgical repair. In other words, the surgeon knows the length of the suture and that it will not substantially change or alter, as opposed to creating such a loop during surgery where there is a chance the length may alter slightly because the knot is loosened or the fibers elongate over time under stress.
Moreover, loops formed by knotting can result in knots that are too large to be used in certain procedures, especially those done using an endoscope or other minimally invasive procedures where space is limited. Also, knots or joints formed during a procedure may slip during or after the procedure and require further surgery and result in a joint that may not fully function.
Looped assemblies are used in a number of minimally invasive procedures. Minimally invasive surgical techniques are increasingly more common because they provide significant advantages due to the decreased level of injury and trauma to the patient. This enables patients to recover quicker and with less pain and discomfort. As a result, more procedures are being adapted for performance by minimally invasive means.
One such procedure is the reconstruction of the ACL (anterior crucite ligament). This procedure is described in detail in U.S. Pat. No. 5,306,301, and incorporated herein by reference. In general, the minimally invasive reconstruction procedure involves drilling a bone passage within the tibia and femur bones at a particular orientation. An attachment assembly is fed through the bone passage. The attachment assembly includes a bone securing device, a ligament (natural or artificial) and a ligament connector. The ligament connector, by its function, is a loop because the ligaments are draped across the loop at one end and fixed to the bone securing device at the other end. The securing device may take the form of an elongated element having the capacity to pass through the bone passage, rotate upon exit, and rest against the bone. The securing device is attached to or incorporated into the ligament connector. The ligament connector may be a knotted suture that connects the ligament to the securing device. The presence of a knotted connector presents the risk of the knot untying or loosening during or after the procedure. A knot may also result in continued irritation to the ligament or other area. Sutures joined by a knot may also create an area of concentrated stress on the ligament and cut into the ligament. This is known as “cheese slicing” and can injure or completely tear the ligament.
There is a need for a continuous loop for use minimally invasive procedures involving the repair or reconstruction of ligaments or tendons, that helps to prevent any tearing, cutting or irritation of the ligament once installed. There is yet a need for a continuous loop that has a relatively smooth exterior so as to support a ligament without irritation. Moreover, there is also a need for a continuous loop without knots, or obvious joints so as to prevent loosening or unraveling of the loop. There is yet a further need for a continuous loop having a specific size or length for use in a number of surgical procedures.